FIFA has charged Luis Suarez with biting Italy defender Giorgio Chiellini in the teams' World Cup match, a process that could lead to the Uruguay player being banned from international competition for up to two years.
Football's governing body said on Wednesday that its disciplinary committee has opened proceedings against Suarez, just hours after the end of Tuesday's match in Natal. Uruguay's officials have been asked to provide their evidence by 8pm GMT on Wednesday.
Suarez, who has been suspended twice before for biting players, was filmed apparently biting Chiellini on the shoulder, before falling to the floor himself clutching his face.
Referee Marco Rodriguez of Mexico did not see the incident and took no action.
FIFA however has the power to act on "serious infringements which have escaped the match officials' attention", it said in a statement. Suarez can be banned for up to two years if he is found guilty of assaulting an opponent.
A decision must be published before Saturday, when Uruguay plays Colombia in a second-round match at Maracana stadium.
The clash happened a minute before Uruguay scored. The match ended 1-0 to Uruguay, meaning they advance from the group stage, while Italy are knocked out.
Suarez has previously been suspended in the Netherlands and England for biting opponents. He did not confirm or deny biting Chiellini, but said he was angry that the Italian defender had hit him in the eye during the game.
FIFA set a World Cup precedent for using video review in 1994: Italy defender Mauro Tassotti was banned for eight international matches for elbowing Spain's Luis Enrique, an incident the referee did not see.